Description: Thallus crustose, continuous to finely rimose around the apothecia, white, pale grey or pale yellowish brown, dull, often delimited by a black prothallus. Apothecia lirelliform, black, raised, oblong to linear, more or less flexuose and branched, often stellate, pointed at ends, 2-10 x 0.15-0.4 mm, with a finally expanded, often grey- to white-pruinose disc, and a up to 10 µm thick proper margin with entire lips; pseudothalline margin absent. Proper exciple black and carbonized laterally, poorly developed and not carbonized at base; epithecium brown; hymenium colourless, not inspersed with oil droplets; paraphyses simple, dense, 1.5-2 µm thick, with brownish tips; subhymenium colourless. Asci 8-spored, cylindrical-clavate, non fissitunicate, dehiscent by an apical split, K/I-, Graphis-type. Ascospores 7-12(-14)-septate with lens-shaped lumina, hyaline, slightly constricted at septa, fusiform-cylindrical, 15-56 x 5-12 µm, the wall I+ blue-violet. Photobiont trentepohlioid. Spot tests: thallus K-, C-, KC-, P-. Chemistry: without lichen substances.
Note: a taxon of the G. scripta-group, characterised by apothecia with mostly acute ends and widely exposed white to grey pruinose discs, found on the bark of broad-leaved trees in various forest types. See also comment on the genus.